Cuantificación del contenido de carbono orgánico edáfico en ecosistemas nativos e intervenidos, en la parroquia Quimiag, cantón Riobamba provincia de Chimborazo.

Abstract

The aim was to quantify the content of edaphic organic carbon in native and intervened ecosystems in the Quimiag parish, Riobamba canton, Chimborazo province. Two samples of 1 kg of soil were collected at two depths: 0-15 cm and 15-30 cm (according to the GIDAC methodology) using a stratified random sampling, 54 samples were obtained at 3 altitudes ranging from 3200 to 3800 m.a.s.l., and the physical and chemical properties of the soil were analyzed. The physicochemical, organoleptic properties and the organic matter content were analyzed by the Loss Ignition method. The results of the organic matter were analyzed using the statistical analysis of variance and comparison of means with Tukey tests and significant mean difference (SMD) at 5% significance using the student statistical program InfoStat. The results indicate that the soils have a pH ranging from strongly acidic to neutral (5-7) according to the international manual of soil fertility, an electrical conductivity of 42.08 to 90.95 μS/cm, granular structure, clay loam texture (mainly), bulk density of 0.47 to 0.84 g/cm3, relative humidity of 42.29 to 62.87%, percentage of organic matter of 12.17 to 18.8%. The organic carbon content in the ecosystems was: 203 MgC/ha in crops, 160.3 MgC/ha in pasture, 147.33 MgC/ha in paramo grassland, 140.01 MgC/ha in forest, 124.7 MgC/ha in forest/paramo. Soils with anthropogenic intervention showed an increase in COS content with respect to the non-intervention, probably due to the contribution of organic matter provided by the deposition of livestock and the addition of nutrients in crops. The ADEVA indicated that soil depth significantly influences COS content (p<0.05) (as soil depth increases COS decreases). It is recommended to assess the anthropogenic activities of ecosystems in the sector (grazing, agriculture) that directly affect the soil.